Roaster School Online - Ep #2 - Drying/Yellowing
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- Опубліковано 20 вер 2024
- Joe brings us past TP in episode #1 and we're looking at the drying/yellowing phase of your roast.
Test your roasting knowledge with our Roaster School 'Year One Quiz', found online at millcityroaste..."
The best way to measure density is with the displacement method in a graduated cylinder. Weigh out a 100.0g sample of your green coffee. Fill you graduated cylinder with enough water that when you put in the 100g of coffee the water will cover it completely. Measure the volume of water in the cylinder and write it down as "initial volume". Put the green coffee in the graduated cylinder with the water. Record the new volume reading as "final volume". The difference between the final volume and initial volume of the water is the volume of the 100.0g sample of coffee. Divide 100.0g by that volume to get a reading in units of g/mL (water = 1.0).
I agree with the comments below, these videos are so valuable to so many people for so many different reasons. Ive seen pretty much every video on this channel and it has helped me so much to better the finish on all of my roasts. Thanks again for everything. I and rarely ever leave comments, so that alone tells you how much I am thankful for these videos. Keep it up.
Q,w
“I’m the Bob Ross of coffee” 😂 love these videos! I’m just getting started on a 5lb drum roaster, and I definitely needed this!
Dear All, please note that i can provide Ethiopian coffee beans with best price directly from our farm. If you are interested let me know. My contact number is 00971555880125.
@@aneesazeezarifa email ?
You are the best roasting school in the world, I love you so much, you really help us a lot😍
Thank you so much for a great videos, We are a coffee roaster in Yemen and we have learned a lot.
Just want to say thank you guys for all of the awesome information. We are very happy we stumbled across your videos, you are a blessing!
EXCELLENT video. Thank you for this content!
Thank you so much for your help by these classes!!!
joe says "the density of the coffee in correspondence with the moisture of the coffee and the size of the coffee will tell you how your coffee seed is going to absorb energy". i am a still confused on how this works...
i'll try to pose my question using the example joe used in the video where you have two 200 mL graduated cylinders and you fill them to the brim with two different coffees with equal moisture content (10%). coffee A (ethiopian heirloom) has a total mass of 125 g and coffee B (marogogipe) has a total mass of 100g, such that the density of ethiopian heirloom is 600 g/L and the density of maragogipe is 500 g/L. coffee A consists of ethiopian heirloom varietals so its graduated cylinder contains 200 beans. coffee B is a maragogipe, which is larger in size, so its graduated cylinder only contains 100 beans. this means that ethiopian heirlooms weigh (on average) 0.625 g/bean whereas maragogipe beans weigh (on average) 1 g/bean.
to me, this means that you'd have to apply more energy to to take the moisture content down from 10% -> 1% for maragogipe bean (10% of 1 g / bean = 0.1g water/ bean -> 0.01g water/bean = 0.09g water loss) and less energy for each ethiopian heirloom bean (10% of 0.625 g /bean = 0.0625 g water / bean-> 0.00625 g = 0.05625 g water loss).
HOWEVER, I would think you'd need to apply the same amount of energy to take the moisture content down from 10% -> 1% for 50 g of marogogipe beans as well as 50 g of ethiopian heirloom beans (10% of 50 g = 5 g -> 0.5 g = 4.5 g water loss). [I've only roasted 50g samples with an Ikawa roaster.]
Does it matter that this 4.5 g water loss would be taking place in 50 marogogipe beans ( 0.09 g water loss / bean) versus 80 ethiopian heirloom beans ( 0.5625 g water loss / bean)?
How does the density measurement factor into any of this?
I am really late to this comment and just thinking out loud here: your logic is absolutely sound as far as I can tell. I think when he says 'energy' he is referencing 'power' in this instance. Beans that have a smaller density will have a smaller thermal conductivity. As such they will have more resistance to a sensible temperature change internally. As such, more dense beans require less heating power to obtain a similar temperature/time profile. I am also thinking that water diffusion through the ink bottle structure plays a role as well (with respect to density).
Don't quote me as gospel on this, but I think that convective heat transfer coefficients for coffee beans are similar across board but conductive heat transfer (internal bean conductivity) varies based on density. Does my thinking seem off? I'd like to hear your thoughts.
This is so incredibly helpful! Thank you for making these videos.
Love the episodes so far! One suggestion - please give the guy who is asking the question a mic or something.
Hey, guys send my thanks for these very important teachings are very very helpful to me
The way you narrate your explanation has helped me understanding coffee roasting. Thanks a lottt! Oh, by the way, love your shirt!! 😊😊😊🥰🥰🥰
The Minnesota Metric System has me bewildered! However, I can't thank you enough for taking the time to make these videos.
How important is it (opinion) for a small commercial roaster (like Mill City customers) to be tracking density/moisture in their roast process?
What tools does one ideally procure for this, apart from scales and graduated cylinders? Thanks again! Happy Cafe Imports customer, btw!
Great videos! I was surprised to hear my local roaster mentioned. I absolutely love Topeca's "seed-to-cup" Ayutupeque, El Salvador.
It should be noted that while your reference to denser materials absorbing heat more effectively is generally correct, your examples are potentially misleading. Thermal conductivity is a property of materials that mirrors electrical conductivity, since heat and electrons move thru materials in a similar fashion. Copper, for example, is a far better conductor of heat and electricity than air; however, the specific heat capacity is something that your space heater example did not consider - specific heat capacity determines the rate at which materials absorb heat. If you have a room full of water and a room full of air, the room full of water, while being a superior conductor, will take much longer to heat up than a room full of air due to the huge difference in the two materials specific heat capacity.
Thank you for mansplaining Joe's 5 year old presentation. 🙄
Guys, great work you are doing!!!
Thanks for sharing!
I am impressed of the presentation, thank you. I learned a lot
Am barista Emmy but much respect to you for explanatory you made
thanks for the videos, very useful!
just one thing, milligrams is a measure of mass not volume, maybe Joe was thinking on milliliters
oh well, there it is
37:40 - one of the many beautiful things about the metric system - 1ml of water weighs EXACTLY 1g. That also connects to distance... one meter cubed of water weights EXACTLY one ton... so cool the system is based around water... with paper sizes, the dimension of an A4 sheet (more or less US letter size) is the same dimension if you fold it in half (that's A5) and if you fold it again, the size is A6 etc... AND A0 is the same dimension but is EXACTLY one meter square in area! NICE EY?
Thanks Joe and the team for the insight to coffee roasting. Please could you explain how can scorching be avoided or reduced as moving from yellowing stage to browning stage?
Reduce heat?
Tks for the videos, guys, I've just began to watch these 2, and will keep watching the others. Regrets from Brazil!!
So when you use a graduated cylinder to measure volume of a solid, you have a problem of the air gaps between the beans. This is dependent on size/shape/packing of the beans. Would it be better to measure the mass of a sample and then submerge the sample in alcohol or low density fluid and measure volume by difference?
Fantastic content. Thank you!!
We learn so much about roasting from your videos. Thank you so much Joe & David, salute from Medan, Indonesia
I think the best way to educate us is to use as number of profiles and pin pointing the issues so that we can learn from there
Дякую за навчання № 2 !
Thanks for uploading these videos. Very helpful.
How do I know how dense or light is my beans?
Most definitely, unless Mill City is an alternate universe that allows time reversal. 😂
That was Joe's superpower.
thanks man. really nice
will lengthening the drying stage help on reducing the sourness on the coffee? (currently facing in Ethiopia Yirgacheffe and Sidama beans)
What happens if I implement 'the soak', turning my heat to super low after dropping in the beans and turning it back up at about 1 minute, is this going to help the heat transfer to get deep into the beans before it moves to maillard reactions?
Thanks for this hugely informative video! I m a home roaster roasting in a convection oven with a drum attachment. Roasts are 16-17mind long on average using the principles you mention (slowing the drying for dense beans) is that too long a roast time?
Very useful
Seems that Temp should be the vertical and time is the horizontal
I think I’m going to try an experiment where I dry some beans to yellow in my oven at a low heat and then roast. I’m a home roasted so I struggle with consistency in color.
That's a very good thing to do to understand the importance of timing your drying phase.
How does the time spent between yellow to FC affect the overall flavour elements of the coffee? Does a fast time to FC take away much of the aroma as compared to a slower one?
I am in multiple coffee forums, but no one appears to have clear answers on how to go about highlighting individual elements of the coffee flavour. Things sound very generic like roast darker for low acidity. Nothing specific on developing body or say sweetness.
Watch Part 1 and 2 of profiling for purpose: ua-cam.com/video/FUseIssQRPs/v-deo.html
And take the 101 class so you can taste the difference : millcityroasters.com/shop/education/roasting-
so the more dense beans, why not put more heat, like rising the temperature, to make it penertrate more quickly, then slow down a little bit to make the temperature fit maillard ?
or make the beans get into the oven with a much higher temperature like more than 200 centigrade, to make it dry more quickly? i kind of lost there
I am a bit confused on the density and speed after turning point, for less densed beans if we are to apply high heat after turning point, wouldn't there be scorching? Or should charge a higher temperature and not apply high heat after the turning?
Really hope to understand on this.. am confused and now sure how to approach bean with different density, should I charge higher or lower, and whether to speed up after turning point.
also confused there....
Love the school
We love you too. 😊
Thanks for sharing @Joe Marrocco. I'm a total newbie on this thing. I have lots of questions about the temperature settings.
What's going to be the problem or the difference If I experience beans yellowing at 110°C after 4 minute roasting and first crack at 150°C eight minutes later. What's the differences in terms of qualities compared with those who experience yellowing at 150°C and first crack at 190°C? Both cases experience drying, maillard & development phases after all, despite the differences in timing & temperature.
Is there any sort of chemical reaction inside the beans that's not going to occur below certain degrees of temperature although the beans colour still reaches the same level of roasting?
Another thing for instance.
If after the drying phase, I use constant temperature (RoR 0°C/minute) lets say 130°C (using PID temperature controller) all the way to the first crack at certain amount of time. What's the quality differences compared with those who generally use steadily rising temperature in roasting the beans?
We still experience the drying, mailard, first crack, development phases though.
I'm so curious. Please let me be enlightened by the Jedi Masters from Mill City Roasters. Lol...
Thanks a lot
Temperature readings are an artifact of thermocouple type and location. Green/yellow transition and first and second crack each occur are specific temperatures. There is no automatic difference in roast quality between first crack observation at 150C and/or first crack observation at 190C. Constant temperature may work perfectly well for you depending on the roaster, batch size, and the coffee.
Steve
@@MillCityRoastersMN super cool answer. Now, it starts to make sense. Thanks Steve.
Water is still present in roasted coffee - it doesn't disappear during "drying" and weight loss is consistent throughout the entire roast...
These guys are classic idiot Americans, they read too much into the process, creating unnecessary metrics, a bunch of esoteric nonsense........................
I kind of want to know if there's a proper weight loss measurement per roast
👍👍
hi Mr john morocco and all north roaster expert . is all these stages and standards important to apply it in AL kind of coffee or just espresso or American coffee ( is it important for Turkish coffee roasting too ) ? and whats the starter flame ( burner ) level i should select if i am new roaster in order to reach yellow stage within 6 mins ?
You should switch the time and ...oh never-mind I see this comment
Why would you use a pipette? I think you mean a beaker, perhaps?
Or a graduated cylinder?
you are great
Does anybody have information concerning the sources he references at 13:39 ish?
14-18c degree p 30sec of bean temp?
hi sir this is sitaram from dubai I love all of this training video this all are so good for learning. I have still confused in what should be rate of heat once we dump the green bean in the roaster and how we can analysis it. would you please help me in this topic
Are you are barista or roaster?
Hi Joe do you use PVC pipe as way to measure density? May I ask how reliable is the result I get from it?
Hi Joe, just watched you video... its very awesome. I have a question. You said the amount of time from green to yellow doesnt effect the flavour...and the range you said generally between 4-6 minutes, my questions is after we reach yellowing point in that range of time, should we increase the heat or lower the heat or make it the same till we hear first crack? Thanks! :)
I believe that depends on how long you want the maillard reaction to happen to your coffee during the roast until the FC. Have you gotten an answer roasting these years? Hope to hear your share of opinion
Lower it,
So when we have coffee which is more moisture then we will have more smoke at the end of roasting?
Uh, no.
@@MillCityRoastersMN ufff ok :)
The seasoning greens that you all recommend for practice, where do these greens fall into as far as density? Would scorching occur when the beans are left in the drum for 20 minutes during the seasoning phase. And can having the drum speed to slow cause scorching? Thanks.
The axes are reversed on this...temp should be on the vertical axis and the time on the horizontal. Cheers
+Dave Borton Since the seasoning greens have unknown variables would it be possible to get scorching on some beans and not others? I have had scorching on all my seasoning roasts.
First time using artisan and I am still very new to this. Thank you.
drive.google.com/open?id=0BwA2DQ4iLMraQnJxS3UwTHNQYnc
+Dave Borton BTW I'm on a 1kg drum roaster. Very similar to AZ1.5 from Buckeye Coffee. I used a 1kg charge.
Noticed this as well. I just auto-corrected in my mind. :)
Türkiye'den herkese selam bu işe yeni giriyorum bilgi için teşekkür ediyorum.
14-18ºF de progresion? Grados Cº???
X 축 - time Y축 - Temp 위치가 바뀐 건 아닌가요 ???
Bob Ross
re: pipette drawing. mg is weight, not volume.
Never mind. You caught it :-)
So does maillard start when we see yellow?
Sort of. There is no real "maillard phase". Maillard starts when the outside of the seed heats to the point maillard can begin and progresses to the interior of the seed as the coffee heats over time. Caramelization occurs at the same time. So the answer to your question is yes, but not as much as it occurs in the interior of the seed after first crack.
A LIKE just for the "...that looks like more of a tongue or a butt..." lol
Okay, actually gave a like before that, but I do like the TONGUE in CHEEK humor...
Sorry to all for that...(hoping that coffee roasters have a silly sense of humor... :-)
My roast machine takes around 8 minutes to dry the Coffe : /
Reduce your batch size.
Hi i would to ask about if the denser beans have 12,5 gram water so it's mean we have use a higher gas while drying ? Than the lower dense ?
Best,
Aldy
aldy antonius
According to Scott Rao,you need higher starting Temperature,with high moisture beans,since you need more energy to expel water or moisture from the inner bean or to be more accurate(The inner core of the bean),the need for higher Temperatures is moisture act's as insulation,which prevents heats reaching the inner core,without a balance temperature between the outer layer of the bean and the inner core at the end of the roast,your coffee technically is under developed.
Ben Hamila
Can I roast 1kg coffee in 600g roaster?
Sure.